@Ryuksgelus:
Thank you. Exact post I wanted to make. Not only that comment but Crocodile's role as a Shichibukai and implied status of a silver medalist makes less and less sense too. I thought Croc's status and Teach's comment on Ace not being hit in a long time was indication that even in the New World being a logia can be relatively smooth sailing until running into somebody near the top as long as you were reasonably tough, skilled, and bright on top of your powers. Now it just seems Oda changed his mind on how rare and special he wanted Haki to be. If Pekom's has Haki and seemingly impressive physical stats then all of WB's division commanders and definitely Doma should be able to hurt Ace regardless of how well if a fighter he is.
Can't see how Croc could gain such a reputation in the New World if seemingly every notable pirate should have been able to take him down or at least stop him from standing out enough to get WB's attention. A line from him about growing weaker while in Alabasta would have excused his status but it doesn't exist. While we're at it why does Moriah not have Haki if once upon a time he faced a Yonkou head-on logically possessing skills and a crew capable of challenging Kaidou's subordinates getting Kaidou's full attention. Is Kaidou just the type to deal with problems on his own and told his goons to back off? Otherwise how did the Moriah Pirates last against a group of Pekoms?
Haki isn't a be all end all defense against Logia. WB stabbed Aokiji with his haki infused spear and Aokiji shrugged it off. Also Jozu slammed Aokiji with what must've been a haki infused attack and coming from someone of such enormous physical strength should've been deadly but again Aokiji acted as if the attack was just a minor delay. Akainu and Aokiji both took physical attacks during the war but none of them came close to doing the damage they would've done to a normal human being. Logia users also have the ranged attack advantage and most of them have a dispersion technique. Caribou, who is obviously an idiot, didn't take advantage of either of those. He actually charged into the fight with a melee weapon. No other logia so far has been that stupid, not even Enel when he realized Luffy was able to physically harm him. I think we can assume that with enough mastery of their fruit and combat intelligence a Logia should not be threatened by Haki users.
Blackbeards DF does two things Haki cannot do. It nulls the DF users power completely. If WB had it, his spear would've gone through Aokiji. If Jozu had it, Aokiji would've been crushed. Whatever suppression Logia users still seem to receive even when hit by Haki attacks would've been removed. The second thing it does is it brings the DF user directly to Blackbeard. The range and dispersion advantages are now gone completely. No matter how fast Luffy is he'll never be as fast as lightening or light. Even with haki his punches can't hurt a sky filled with snow, a room filled with smoke, or a storm of sand. I don't expect a fighter as good as Ace to have been hit very often and even if he had it was never with without some protection from being a Logia.
As for crocodile, his reputation comes not just from his fruit, which he has mastered, but also from his intelligence which is one of the highest so far. Just having Haki isn't enough to beat someone like him. Luffy lost twice and in all three of those fights crocodile severly underestimated him. I think you're thinking about Haki and Logia in terms of like power levels which doesn't make sense here. It's not Haki>Logia>Zoan>Paramecia. Haki and the DF and just tools or weapons to be used in a fight. In most cases it depends on the person using the fruit/haki that will decide the outcome of a particular encounter rather than having the Fruit/Haki itself though having one or the other obviously increase the damage you can do in a fight.